computer graphics in the 1950s

Tony Duell ard at p850ug1.demon.co.uk
Sat Oct 18 14:59:23 CDT 2008


> 
> On 17 Oct 2008 at 21:38, Tony Duell wrote:
> 
> > Did anyone try using 3 monochrome CRTs and combining the outputs 
> > optically (e.g. by back projectuion)? That would get round the need for a 
> > shadowmask 
> 
> As Fred mentioned, projection TVs (I still see them), but convergence 
> was a headache. The fewer optics, the better.  Better to use field-
> sequential with a color wheel (as in the old CBS color TV system) as 
> various computer-to-film systems did.
> 
> If you've never seen one, the color on the old CBS system was quite 
> good--far better than the RCA shadowmask tubes of the time.
> 

Of course the problem, for TV, was that the signal was not compatible 
with the monochrome system (in either direction). That was, I believe, a 
major reason for not using sequential colour systems.

Of course this doesn't apply for vector graphics displays, and thinking 
about it, at least one vector display system did use a rotating colour 
wheel on a spectacle-like frame in front of the useres eyes. Not only did 
this give colour, but also a 3D effect (the wheel could blank off each 
eye alternately so that you could have the 2 images of a stereo pair 
viewed by each eye). The machine I am thinking of is, of course, the 
Vectrex video game. The colour/3D spectacles are, alas, very hard to find.

-tony



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